<!DOCTYPE html>
<head>
  <meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<canvas id="canvas" width="300" height="300" style="border:1px solid #000000;"></canvas>
<script>
var c = document.getElementById("canvas");
var ctx = c.getContext("2d");
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(300, 300);
ctx.stroke();
</script>
</body>
</html>
